The mammalian heart lacks significant regenerative capacity. In vitro generation of cardiac cells in quantities sufficient for transplantation would therefore revolutionize the treatment of heart disease. A recent report of successful transdifferentiation of somatic cells to a cardiac fate in vitro (Ieda, M. et al., Cell 142, 375-86 (2010)) has raised the possibility that this process might eventually be used for cell-based cardiac therapy. However, speed and efficiency must first be improved, especially if the ultimate goal is to provide a faster and safer alternative to the re-differentiation of autologous induced pluripotent stem cells (iPSCs) (Schenke-Layland, K. et al., Stem Cells 26, 1537-46 (2008)).